Improvement in saw-sharpening machines



P. D. ROBBINS.

SAW-SHARPENING MACHINE.

N`o.187,909 Patented Feb. 27,1877.

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ATTUBNEYS.

NPEERS. PHOTO-LITHOGRAPHER. WASHINGTON. D C

UNITED STATES PATENT EEICEc PARKER D. ROBBINS, OF HARRELLSVILLE, NORTH CAROLINA.

IMPROVEMENT IN SAW-SHARPENING MACHINES.

Specification forming part of Letters Patent No. 187,909, dated February 27, 1877; application filed September 2, 1876i To all whom 'it may concern Be it known that I, PARKER D. RoBBrNs, of Harrellsville, county of Hertford, and State of North Carolina, have invented a new and Improved Saw-Sharpening Machine.0f which the following is a specification:

Figure 1 is a side elevation. Fig. 2 is a bottom View. Figi?, is a perspective view of theV circular tile.

Myinvention consists of a circular or rotary tile having a diagonal groove on its face for carrying the saw forward, placed on a suitable mandrel, and a turn-table, to which the saidmandrel is journaled, and which can be adjusted to give .the proper bevel to the teeth being tiled.

The object of the invention is to rapidly file the teeth of a saw at any desired bevel, by rotating the le by means ot' a crank and suitable gearing, the saw being drawn forward by the diagonal slot in the edge of the file.

Similar letters of reference indicate corresponding parts.

A is the frame of the machine, consisting of the bars a a, slotted end pieces b c, and bar d. B -is a circular socket, attached to thev bars a a of the frame A, for receiving the turn-table O, and is provided with a set-screw, e, for holding the turn-table in any desired position. D is a lever attached to the turn-table for the purpose of adjusting it. A mandrel, E, carrying a rotating le, f, is placed centrally in the turn-table, and is provided with journalboxes g, that are attached to the turn-table. F is a shaft, provided with the crank h and bevel-wheel i, and is provided with journalboxes attached to the turn-table. The bevelwheel meshes with a pinion, j, on the 'mandrel E. The circular tile f is provided with a slot, 7c, across its face for moving the saw forward, and is beveled to give the required form to the saw-teeth. The saw Gis placed against the brace or guide l, with a tooth at its heel resting on the rotary le. It is pressed against the guide l by the spring m, and is held down upon the Iile by the spring n, which carries the grooved friction-roller o, that rests on the back of the saw. The pressure of this spring is increased or diminished by turning the setscrew p.

On rotating the file by means of the crank h the teeth are sharpened,and moved forward by the slot la, which moves the saw one tooth forward at every revolution when the teeth are tiled straight across; but when the teeth are to be beveled, the slot must be of such pitch as will carry the saw forward by engaging with alternate teeth, and the saw must be run through the machine twice, t0 give the required bevel to the alternate teeth. The iile is adjusted to any desired bevel by loosening the screws, and turning the table G in one direction or the other by means of the lever D. Files of different forms and pitches are used for di'erent sizes and forms of teeth.

I am aware that it is not new to use a r0- tary file provided with two screw threads having twice the pitch ot the teeth, or to use a spiral feeding-blade; but

IVhat I claim is- 1. The combination, with the guide l and lateral spring m, of the grooved roll 0, and springpresser on the top ol' saw, as shown and described, to hold the saw with a yielding pressure.

2. The combination of the turn-table O, shaft F, crank h, Wheelt', mandrel E, pinionj, rotary le f, socket B, set-screw e, springs m n, set-screw p, and frame A, substantially as and for the purpose specified.

PARKER D. ROBBINS. Witnesses:

N oRMAN H. SHAW, ZAcHEUs EARLY. 

